Load support diffuser and method of manufacture

ABSTRACT

THERE IS DISCLOSED HEREIN A LOAD SUPPORT DIFFUSER ADAPTED TO SUPPORT A VERTICAL STACK OF COILS IN AN ANNEALING FURNACE AND DIFFUSE A PROTECTIVE ATMOSPHERE GAS WITHIN SAID FURNACE, THE DIFFUSER COMPRISING A FLAT CIRCULAR BASE PLATE, VSHAPED FLOW DIVIDER MEMBERS MOUNTED ON TOP OF THE PLATE AND HAVING THE APICES THEREOF DIRECTED INWARDLY TO DEFINE A CENTRAL FLOW PASSAGES, DEFLECTORS FOR DIFFUSING THE GAS UPDIRECTED FLOW PASSAGES, DEFLECTORS FOR DIFFUSING THE GAS UPWARDLY AT THE OUTER ENDS OF THE FLOW PASSAGES, AND A DOUBLE LAYER OF OPPOSITELY SKEWED SUPPORT BARS CARRIED BY THE FLOW DIVIDER MEMBERS.   D R A W I N G

Feb. 13, 1973 R. 1.. CORBETT, JR 3,

LOAD SUPPORT DIFFUSER AND METHOD OF MANUFACTURE Filed Feb. 10, 1971 2Sheets-Sheet 1 JJO I K &W ".43/

/NVEN7'OR Robert Lee Corbezi, J1:

J. H. SLOUGH ATTORNEY F 1973 R. L. CORBETT, JR 3,716,223

LOAD SUPPORT DIFFUSER AND METHOD OF MANUFACTURE Filed Feb. 10, 1971 2Sheets-Sheet 2 J0 72 5/ 75 3/ 5/ 6/ L 5/ L g 59 5g I I l I" "I 53 60 -6259 r l 1 f) 4% .I. v I I 1 57 [I 44 57 I 5 31 1M, A 1 4 W 52 LA 1 A7'7'OR NEY United States Patent Oflice US. Cl. 432-460 9 Claims ABSTRACTOF THE DISCLOSURE There is disclosed herein a load support difluseradapted to support a vertical stack of coils in an annealing furnace anddiffuse a protective atmosphere gas within said furnace, the diffusercomprising a flat circular base plate, V- shaped flow divider membersmounted on top of the plate and having the apices thereof directedinwardly to define a central opening for a blower and defining outwardlydirected flow passages, deflectors for diffusing the gas upwardly at theouter ends of the flow passages, and a double layer of oppositely skewedsupport bars carried by the flow divider members.

This invention relates to annealing furnaces adapted for treating coilsof strip metal and relates more particularly to a load support dilfuseradapted to both support a charge of coils stacked endwise within afurnace and also diffuse a protective, nonoxidizing atmosphere gaswithin the furnace.

In a known form of the type of furnace referred to, the coils of stripmetal are stacked coaxially upon a suitable base structure and have arecirculating fan or centrifugal blower disposed therebelow. Each coilhas a coaxial central opening or eye, and the blower is adapted tocirculate a heated, protective atmosphere gas upwardly around theoutside of the coils and downwardly through the eyes of the coils, or tosimilarly circulate a cooling gas. Coil separators or convector platesare preferably providel between adjacent coils, said separatorsproviding passage means allowing the gas to circulate between the coilsand across the edges of the coil wraps. The stacked coils are preferablyclosed within a gastight inner cover which is, in turn, disposed withina suitable furnace having radiant tube burners or other suitable heatingmeans for heating the inner cover and the atmosphere gas confined withinthe inner cover.

It will be readily apparent that the load support means in the abovetype furnace is subjected to substantial pressures in use due to thefact that it supports the entire weight of all of the coils. It willalso be apparent that the load support is subject to a wide range oftemperature changes which tend to cause said support to distort. A loadsupport of the type herein disclosed is substantially hollow, passagemeans being provided therein for rapidly diffusing and recirculating thegas whereby the problem of structural strength anl distortion due totemperature changes are accentuated. Reinforcing structure must notinterfere with the circulation of the gas and at the same time must besuflicient to aflord a strong, durable structure not subject todistortion under pressure and temperature changes. Additionally, it isimportant that the load support have an upper, load bearing surfacehaving an area suflicient to prevent damage to the edges of the coilwraps. These and many other problems which are encountered in connectionwith the manufacture and use of load supports of the difluser type havebeen solved in an improved manner by the invention disclosed herein.

The general object of the invention is to provide an improved loadsupport dilfuser as set forth above having imp 3,716,223 Patented Feb.13, 1973 in an annealing furnace and diffusing an atmosphere gasthereto.

Another object of the invention is to provide an improved load supportdiffuser as set forth above having improved passage means therein fordiffusing the heated atmosphere gas from below a stack of coils.

Still another object of the invention is to provide a load supportdifluser so constructed as to resist distortion due to extremetempearture changes.

Yet another object of the invention is to provide a load supportdiffuser having supporting surface means suflicient to support the coilswithout damage to the edges of the coil wraps, said support alsoaffording adequate circulation of the atmosphere gas across the axiallydirected ends or edges of the coil wraps.

A still further object of the invention is to provide in combinationwith a load support diffuser set forth above, centering means forcentering the inner cover with respect to the charge.

A still further object of the invention is to provide, in combinationwith a load support of the above type, deflector means at the outer endsof the pass-age means for deflecting the gas upwardly around the charge.

Yet another object of the invention is to provide improved means formounting the deflector means of the foregoing object.

Another object of the invention is to provide a load support diffuser asset forth above which is of simple, sturdy construction, inexpensive tomanufacture, and highly durable in use.

Other objects of the invention and the invention itself will be readilyapparent to those skilled in the art to which it appertains uponconsideration of the following description of the invention and theaccompanying drawings, in which said drawings:

FIG. 1 is a fragmentary longitudinal section through the lower baseportion of an annealing furnace containing a stack of strip steel coilsdisposed upon the load support diffuser of this invention;

FIG. 2 is a substantially enlarged, generally top plan view of thedilfuser with certain portions thereof being removed to clarify theconstruction;

FIG. 3 is a section taken along the line 3-3 of FIG. 2;

FIG. 4 is a section taken substantially along the line 4-4 of FIG. 2;

FIG. 5 shows the outer end of one of the flow passages as seen from theline 5- -5 of FIG. 2; and

FIGS. 6 and 7 show two steps in the method for manufacturing the loadsupport diffuser of this invention.

Referring now to thedrawings in all of which like parts are designatedby like reference numerals, FIG. 1 shows, in section, the lower portionof a hood or bell type furnace 10 comprising a cylindrical body portion11 and a suitable refractory lining indicated at 13. The cylindrical'body portion 11 is preferably formed of heavy sheet metal and has adownwardly projecting, annular flange portion 14 which projects into agranular sealing trough 15 of a generally cup-shaped 'base 16. The basehas an upwardly projecting, annular flange 17 having a slightly largerdiameter than the flange portion 14 whereby said flange portion 14 isdisposed generally within said annular flange 17. The body portion 11 issupported by radially projecting fins 18 the bottom edges of which seatupon the upper edge of the annular flange 17. The base 16 also includesa suitable refractory bottom lining 19 and a central support structurecomprising concentric steel rings 20 having refractory material 21disposed therebetween. An annular plate 22 surrounds the concentricrings 20, and a larger annulus 23 is disposed outwardly therefrom andforms the inner wall of the granular sealing trough 15. Said trough isfilled with a suitable granular sealing material such as sand, intowhich the flange portion 14 projects.

The base 16, as herein illustrated, is securely mounted upon I-beams 24which are seated in a concrete floor 25 or other suitable supportingmeans, A central cavity 26 in the floor 25 affords space for mounting amotor 27 having a shaft 28 which projects upwardly through the centralportion of the base 16, the upper end of said shaft carrying acentrifugal fan or blower 29. The blower 29 is disposed within a centralopening 31 of the load support diffuser of this invention, said loadsupport diffuser being generally indicated at and being hereinafterfully described in detail in connection with FIGS. 2-7. An atmospheregas inlet 30a and an atmosphere gas outlet 30b project upwardly throughthe base 16 into said load support diffuser at the periphery thereof.

The diffuser 30 supports a plurality of coils 32 of strip sheet metalstacked vertically and coaxially within the body portion 11, only thebottommost of said coils being shown in FIG. 1. It will further beunderstood that the coils are preferably separated by coil separators orconvector plates (not herein illustrated) as is well-known to thosefamiliar with the art. Each coil defines a central opening or eye 34,the eyes of all of the coils being aligned to provide a central openingthrough the stack of coils.

A cylindrical inner cover 37 is disposed over the stacked coils 32, saidinner cover having a lower, annular base portion 39, which seats uponthe annular plate 22 outwardly of the gas inlet 30a and gas outlet 30band is sealed thereto by granular sealing means, such as sand, indicatedat 39. In the form of the invention shown, heating means for the furnacecomprise elongated, gasfired radiant tube heaters 40 which are evenlycircumferentially spaced around the outside of the inner cover 37 withinthe refractory lining 13.

Referring now to FIGS, 2 and 3, the load support diffuser 30 comprises acircular metal base plate 43 having a central aperture 44 through whichthe shaft 28 of the motor 27 projects. The base plate 43 seats upon theupper edges of the annular rings 20 with the outer circumferential edgeportion thereof overlapping the annular plate 22. The centrifugal blower29 is disposed above the base plate 43 and circulates the protectiveatmosphere gas radially outwardly with respect to said base plate.

The upper surface of the base plate 43 carries a plurality ofcircumferentially spaced, V-shaped flow dividers adapted to definepassages 58 therebetween for directing the outward flow of theatmosphere gas. As herein illustrated, the flow dividers 50 are metalmembers which extend from points adjacent to the outer periphery of thebase plate 43 inwardly to points adjacent to the inner peripherydefining the central aperture 44 of said base plate. Each flow dividercomprises a pair of diverging walls 51 and 52 which, in the form of theinvention herein illustrated, are made from heavy, thick bar stockdisposed on one side edge thereof and welded to the upper surface of thebase plate 43. As herein illustrated, the wall 51 is relatively longerthan the wall 52 and extends inwardly to a point closely adjacent to theedge of the aperture 44, its inwardly directed portion having a shorttaper or bevel 53 to afford a sharp inner end to the flow divider 50.The arm 52 converges inwardly with the arm 51 intersecting the sameadjacent to the bevel 53 and being itself angled or beveled at 54adjacent to said wall 51 at an angle equal to its angle of convergence.The two walls 51 and 52 are rigidly welded together as well as beingwelded to the base plate 43. It will be noted that the elongated walls51 and 52 are welded to the base plate 43 at separated areas asindicated by welds 55 at their outer ends, short welds 56 adjacent tomedial portions and where the walls converge, and welds 57 adjacent tothe ends of said walls. This discontinuous or stitch welding allows fora differ- 4 ence in the rate of expansion and contraction of the baseplate 43 and the heavy bar stock of the walls 51 and 52.

The flow dividers 50 are so disposed upon the base plate 43 that theircenter lines are skewed in the same circumferential direction withrespect to true radii of the base plate. The said flow dividers arecircumferentially spaced apart whereby to provide therebetween the gasflow passages 58 which extend from a point adjacent to the centralaperture 44 outwardly to a position adjacent to the outer periphery ofthe base plate 43. The passages 58 widen slightly in the outwarddirection, their outer end portions being provided with outwardly andupwardly angled deflector plates 59.

Referring now particularly to FIGS. 3 and 5, each deflector plate 59 asherein illustrated is disposed at substantially a 45" angle and extendslaterally substantially the full width of the passage between twoadjacent flow dividers 50. However, it will be noted that neither sideedge of the deflector plate is welded to the adjacent wall 51 or 52.Each deflector plate 59 is welded on both sides of its lowermost edge tothe upper surface of the base plate 43 as indicated by the welds 60 and61 in FIGS. 3 and 5, respectively. Each deflector plate is further supported by a vertically disposed, centrally located triangular gussetplate 62 which is welded to the lower surface of said deflector platealong an angled edge 62 thereof, and to the base plate 43, by welds 63and 64, respectively. Thus each deflector plate 59 is firmly anchored inits respective passage way but is unaffected by relative expansion andcontraction of adjacent flow dividers 50 and the circular base plate 43.

From the foregoing it will be readily seen that the gas flow passages 58are angled or skewed with their inner ends being offset in acounterclockwise direction with respect to the outer ends thereof, Thepassages are thus adapted to receive outflowing gas impelled by thecentrifugal blower 29 which rotates in a clockwise direction.

Each of the flow dividers 50 carries a flat bar of substantially heavymetal stock, said bar tapering inwardly along its side edges andterminating at its inner, smaller end radially inwardly a slightdistance beyond the inner ends of said flow dividers. The outermost edge71 of each said bar is disposed radially outwardly from the outer endsof the flow dividers and radially outwardly beyond the outwardly andupwardly disposed edges of the deflector plates 59. The bars 70 aredisposed substantially in alignment with the flow dividers 50 andcompletely cover the V afforded by the angled walls 51 and 52. Each bar70 is substantially angled or skewed with respect to a true radius ofthe base plate 43, all of said bars being skewed the same amount in thesame circumferential direction.

A second layer of flat bars is superimposed upon the layer of bars 70.The bars 75 are the same shape as seen in plan view as the bars 70 butare skewed or angled in the opposite circumferential direction wherebyeach said bar 75 overlaps three of the bars 70. It will be noted thatthe outermost edges of the bars 75, indicated at 76, are inset slightlyin a radial direction with respect to the outermost edges 71 of the bars70. This results in the innermost edges 77 of the bars 75 inwardlyoverhanging or projecting inwardly beyond corresponding innermost edges69 of the bars 70.

Each bar 70 is welded to the upper edges of the flow divider walls 51and 52 by a pattern of welds similar to those welding the flow dividersto the circular base plate 43. The outer ends of the walls 51 and 52 areprovided with welds 72 which extend across the ends of the walls and ashort distance along either side of each wall. Intermediate welds areprovided as indicated at 73, and V- shaped welds 74 secure the innermostend portions of the walls 51 and extend around the angle or bevel 53.The overlapping flat bars 75 are welded to each other in a uniformmanner from above and below the layers of overlapping bars. Welds 78connect the outermost edges 76 of the flat bars 75 to the upper surfacesof the flat bars 70 adjacent to their outermost edges 71. It will benoted that the welds 78 also extend around one corner of each bar 75 andpartway along one side edge. The welds 78 also extend around theopposite corners of the underlying, associated flat bars 70 whereby anedge portion of each said flat bar 70 is welded to the lower surface ofthe associated bar 75. In the area where the larger, outer ends of thebars 70 and 75 overlap, substantially long overlapping edge portions areprovided with discontinuous or broken welds as indicated by the shortweld portions 78' spaced inwardly from the inner ends of the welds 78.In the areas where the intermediate portions of the bar 75 overlapintermediate portions of the bars 70, said overlapping bars aresimilarly welded from both above and below by intermediate welds 79.Where the innermost ends of the bars 75 overlap the innermost ends ofthe bars 70, the bars are firmly anchored together by welds 80 on boththe upper surfaces of the bars 70 and the lower surfaces of the bars 75.Thus it will be seen that all of the bars 70 and 75 are firmly andrigidly secured together and to the flow dividers 50, and that in eachinstance where long, overlapping edge portions are welded to anothermember, a discontinuous weld connecting the members at separated areasis used to allow for different amounts of expansion and contraction ofthe different members. Allowing for relative expansion and cntraction ofthe parts is important to prevent distortion of the diffuser in use andis necessitated, in part, by the various metal thicknesses and masses ofthe different parts. For example, the bars 75 are preferably of thinnermaterial than the bars 70 which in turn are less massive than the stockused to form the flow dividers 50.

It will be noted that in four circumferentially evenly spaced flowdividers 50 there are provided modified walls 52, said modified wallsbeing indicated at 52. The walls 52. differ from the walls 52 in thatthey extend outwardly beyond the outermost edges 71 of the flat bars 70and are provided with curved upper edge surfaces 81 which curvedownwardly and outwardly as best seen in FIGS. 3 and 4. The curvedsurfaces 81 provide means for guiding the inner cover 34 into asubstantially concentric position with respect to the stack of coils 32.

A fan guard 90 is carried over the centrifugal blower 29 for protectingsaid blower from the load carried by the support diffuser 30. Said guardcomprises an outer ring 91 having outwardly projecting teeth 92 soshaped and angled that they are adapted to project between the innerends of the bars 75 and rest upon portions of the bars 70 which theyoverlap. Thus the guard is supported at a plurality of points above thecentrifugal blower 29. Said guard also has an inner protective ring 93integrally connected with the outer ring 91 by means of braces 94-.

The teeth 92 of the blower guard 90 are not secured to the bars 70' butmerely rest thereon whereby said guard can be readily lifted out tofacilitate removal, repair, and inspection of the blower. The teeth 92stabilize and prevent distortion of the inner ends of the bars 75 andgenerally lock those parts associated with the center of the loadsupport into position. The radially disposed braces 94 prevent the innerwraps or coil tails from being drawn downwardly into the blower. It willalso be noted that the teeth 92 and ring 91 block the upper part of thepassages between the bars 75. This prevents the flow which is beingforced radially outwardly by the blower from short circuiting; that is,immediately re-entering the blower adjacent to its upper end due to thesubstantial negative pressure present at the top of the blower. Byblocking reverse flow at this point, better and more eflicientcirculation is achieved.

FIG. 6 shows the manner in which the walls 51 and 52 of the flow divider50 are welded to the circular base plate 43-. When the bars comprisingthe walls 51 and 52 are welded to the base plate, said base plate tendsto bow upwardly at its outer edges in a slightly upwardly concave form.When such a diffuser is used to support a stack of coils 3 2, the outeredges are pressed downwardly thereby creating substantial stresses atthe welded connections. To ofiset this, the base plate 43 is placed upona substantially heavier, relatively nonfiexible backup plate 100 havinga flat upper surface 101. The inner peripheral edge portion around thecentral aperture 44 is blocked upwardly in any suitable manner such asby a plurality of small blocks 102. The outer peripheral edge portion ofsaid base plate 43 is then clamped tightly down against the uppersurface 101 of the backup plate 100 by any suitable means such as Cclamps 103. With the base plate 13 held in this upwardly convexposition, the bars formmg the walls 51 and 52 of the flow divider 50 arewelded to the base plate as indicated at the welds 5557. After all ofthe flow dividers 50 have been welded in place, the C clamps 103 arereleased whereby the base plate 43 springs back to its normal fiatposition. Thus when the bars and are welded in place to complete thediffuser, said diffuser can be loaded without creating additional stressto the welded connections.

As best shown in FIG. 2, the bars 70 and 75 are circumferentially spacedfrom each other whereby the atmosphere gas which flows outwardly throughthe gas flow passages 58 can also flow across the bottom edges of thecoil wraps directly supported by the support diffuser 30. Because of thenegative pressure above the fan, a small amount of the outgoing air isdrawn back between the bars 75 of the top layer thereby inducing aturbulence at the open areas and between said bars 75 which im provesthe heating or cooling of the coils. As hereinbefore noted, theatmosphere gas cannot return all the way back to the fan due to the ring91 of the fan guard 90.

By placing the flow dividers directly and completely underneath thefirst layer of bars 70, the entire load carrymg capacity of the diffuseris enhanced and this is particularly true at the inner ends of said bars70 and 75. The inner tips of the walls 51, beveled at 53, are preferablysubstantially sharp whereby the air can escape the fan with the leastamount of restriction. It is possible to make this edge quite sharp byuse of the short bevel 53 without sacrificing substained strength at theiner ends of the bars 70 and 75. The gas flow passages 58 widen slightlytoward their outer ends whereby to eliminate any restriction of the fansflow of gas and to maintam the velocity of the gas emitting from the fanor blower 29.

The interconnection of each bar 75 with at least three of the bars 70 ineffect ties each flow divider 50 with at least four other flow dividersthereby providing a structure of great strength which effectivelyresists warping and twisting when subjected to exterior pressures andsubstantial temperature changes. The bars 75 also provide sufficientload bearing areas to prevent damage to the edges of the coil wraps. Bypreventing warpage, the upper surfaces of the bars remain level therebymaintainin a maximum area of contact with the coil wraps for efficientheating by conduction.

It will be further understood that many changes in the details of theinvention as herein described and illustrated may be made without,however, departing from the spirit thereof or the scope of the appendedclaims.

I claim:

1. A load support diffuser for supporting stacked coils in an annealingfurnace comprising a base plate having a vertical axis; said base platecomprising fiat plate metal; a plurality of flow dividers carried on theupper surface of said base plate; said flow dividers comprising V-shaped members the apices of which project inwardly and define a centralopening adapted to receive a blower; said V-shaped members beingcircumferentially spaced around said opening and being skewed withrespect to true radii of said base plate in one circumferentialdirection; said flow dividers defining gas flow passages therebetweenwhich are skewed in said one circumferential direction and are adaptedto direct a flow of atmosphere gas outwardly for diffusing said gaswithin an annealing furnace; each said flow divided member having a flatsupport bar mounted horizontally thereon and disposed substantiallyparallel therewith whereby said support bars are skewed in the samemanner and direction as said flow dividers; said support bars beingcircumferentially spaced from each other whereby said gas flow passagesare open at the top; other flat, circumferentially spaced support barsoverlying and secured to said first mentioned support bars; said othersupport bars being skewed in the opposite circumferential direction withrespect to said first mentioned support bars whereby each said othersupport bar overlies a plurality of said first mentioned support bars,there being portions of said gas flow passages completely open at thetop whereby atmosphere gas from said passages is adapted to flowupwardly directly against the end of a coil seated on said diffuser andinto the spaces between said other support bars.

2. A load support diffuser as set forth in claim 1: said V-shapedmembers being uniformly circumferentially spaced around said opening andbeing skewed with respect to true radii of said base plate in a uniformmanner; and said first mentioned support bars and said other supportbars being inwardly tapered and circumferentially uniformly spaced.

3. A load support diffuser as set forth in claim 1: each said othersupport bar overlying three of said first mentioned support bars.

4. A load support diffuser as set forth in claim 1: outwardly andupwardly angled, flat deflector plates disposed adjacent to the outerends of said gas flow passages adapted to deflect the gas upwardly atthe outer periphery of said load support diffuser; each said deflectorhaving its inner, lowermost edge welded to said base plate and extendingvertically substantially the height of said flow dividers; side edges ofeach said deflector plate being disposed closely adjacent and unattachedwith respect to flow dividers on either side thereof; a brace memberdisposed under each said deflector plate, said brace member having anangular portion welded to the lower side of the deflector plate andbeing welded to the base plate to support the deflector plate free ofsaid adjacent flow dividers.

5. A load support diffuser as set forth in claim 1: the apex of eachsaid flow divider terminating in a substantially sharp, vertical edgewhereby to reduce the restriction of gas emitted by the blower.

6. A load support diffuser as set forth in claim 5: each said flowdivider comprising a pair of straight, inwardly converging walls, one ofsaid walls projecting inwardly beyond the other said wall; said one wallhaving a short bevel at the inner end thereof, said bevel being in avertical plane and converging with one side of said one wall to formsaid substantially sharp, vertical edge.

7. A load support diffuser as set forth in claim 6: said walls beingwelded along the upper and lower edges thereof to said first mentionedsupport bars and said base plate, respectively, and certain long,overlapping portions of said first mentioned support bars and said othersupport bars being welded, by discontinuous welds whereby substantialportions of the overlapping parts are free to move with respect to eachother to allow for separate expansion and contraction of said walls andsupport bars.

8. A load support diffuser as set forth in claim 1: each said flowdivider comprising a pair of straight, inwardly converging walls;certain of said flow dividers having one of said walls projectingoutwardly a substantial distance beyond the other of said walls, theoutwardly projecting portion having an outwardly and downwardly curvedouter end, there being a plurality of said projecting wallscircumferentially spaced around said diffuser and adapted to cooperatein guiding a cylindrical cover into a substantially concentric positionwith respect to said diffuser.

9. A load support diffuser as set forth in claim 1: said flow dividersdefining gas flow passages which widen slightly toward the outer endsthereof to maintain the velocity of gas emitted from a blower.

References Cited UNITED STATES PATENTS 3,149,827 9/1964 Whitten 263-473,423,079 1/1969 McKeown 263-47 3,586,302 6/1971 Corbett, Jr. 263473,618,921 11/1971 Corbett, Jr. 26347 X KENNETH W. SPRAGUE, PrimaryExaminer a NITED S ATES PATENT OFFICE CERTIFICATE OF to ECTWN Patent Noa DatedFe'brua'ry 13 I 1973 Inventorts) Robert ie fbetv Jr;

It is certified that error appears in the =aboveidentified patent andthat said Letters Patent are hereby corrected as shown below:

Page 1, column 1, lines 70 and 71 and column 2, lines 1 and 2 should bedeleted and the following inserted therefor! v "The general objectof theinvention is to provideanfimproved l'oadsupport diffuser forsupportin'ga stack of coils in an annealing furnace -anci 'diffusinganatmosphere'gas thereto."

. Signeclhand sealed thislOth day of July 1973.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. I Rene Tegtmeyer Attestlng Officer 1 ActingCommissioner of Patents F ORM F'O-1050 (10-69) USCOMM-DC 60376'P69 U.SGOVERNMENT PRINTING OFFICE: 1569 0-366-334

